At present, according to the conclusion of Service and System Aspects 2 (SA2) Workgroup, an ongoing MBMS session may change some service characteristics, for example, Service Area. An Evolved Packet Core (EPC) network defines an MBMS Session Update procedure. However, in a radio access network (RAN), there is no corresponding procedure definition especially in M3 (an interface between a Mobility Management Entity MME and a Multi-cell/Multicast Coordination Entity MCE) and M2 (an interface between the MCE and an eNB) interfaces. Upon receiving an MBMS Session Update Request message from a Broadcast/Multicast Service Center (BMSC), an MBMS gateway sends different messages to the MME based on different results of comparison between an updated control node list included in itself and the updated control node list included in the MBMS Session Update Request message, wherein the different messages may be MBMS Session Start Request, MBMS Session Stop request, and MBMS Session Update Request. The MME needs to send these messages to its corresponding MCE. Therefore, in the M3 and M2 interfaces, processing of the MBMS Session Update procedure needs to be defined. The processing comprises a new M3 application protocol (M3AP) and M2 application protocol (M2AP) signaling flow definition for the MBMS Session Update procedure, and a relevant processing mechanism for MBMS Session Update signaling of the M3AP and M2AP in the MCE and eNB.